Intermediates for herbicidal sulfonamides

ABSTRACT

This invention relates to novel o-carbonylbenzenesulfonyl isocyanates and their use as intermediates for the preparation of sulfonylureas which are known to be active herbicides.

RELATED APPLICATIONS

This is a division of application Ser. No. 119,165, filed Feb. 6, 1980,which is a continuation-in-part of my copending application U.S. Ser.No. 049,149, filed June 18, 1979, which is a continuation-in-part of mycopending application U.S. Ser. No. 029,281, filed Apr. 13, 1979.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 3,484,466 teaches a process in which an aromaticsulfonamide is phosgenated in the presence of an inert solvent and acatalytic amount of a hydrocarbyl isocyanate to form the correspondingarylsulfonyl isocyanate. 4-Isocyanatosulfonylbenzoate ester is listed asa compound which can be prepared by this method.

In U.S. Pat. No. 3,379,758 arylsulfonyl monoisocyanates and arylsulfonyldiisocyanates are produced by a process which comprises mixing in therange 0° to 175° C., phosgene and an arylsulfonylurea of the formulaAr(SO₂ NHCONHR)_(n), wherein n is one or two, R is alkyl of one to 8carbon atoms, inclusive, and Ar is phenyl or phenylene, unsubstituted orsubstituted with one or two substituents selected from the classconsisting of alkyl of one to 8 carbon atoms, inclusive, cycloalkyl of 3to 8 carbon atoms, inclusive, phenyl, naphthyl, aralkyl of 7 to 10carbon atoms, inclusive, alkoxy of one to 8 carbon atoms, inclusive,halogen, nitro, cyan, sulfo, amino, dialkylamino of 2 to 12 carbonatoms, inclusive, and alkoxycarbonyl of 2 to 8 carbon atoms, inclusive.

In U.S. Pat. No. 3,371,114 there is taught a process of converting anaromatic sulfonamide to the corresponding aromatic sulfonyl isocyanates.Phosgenation of the sulfonamide in the presence of a catalytic quantityof a hydrocarbyl isocyanate gives the desired sulfonyl isocyanate.

SUMMARY OF THE INVENTION

None of the above references teach the intermediates necessary to makean improved class of highly active herbicidal sulfonylureas taught inU.S. Ser. No. 029,281. According to the instant invention, such anintermediate has been discovered. The intermediate has the generalformula: ##STR1## wherein R is C₁ -C₁₂ alkyl; C₃ -C₁₀ alkenyl; C₃ -C₁₀alkynyl; C₂ -C₆ alkyl substituted with one to four substituents selectedfrom 0-3 atoms of F, Cl, Br or 0-2 methoxy groups, C₃ -C₆ alkenylsubstituted with 1-3 atoms of F, Cl or Br; C₅ -C₈ cycloalkyl; C₅ -C₈cycloalkenyl; C₅ -C₈ cycloalkyl substituted with substituents selectedfrom one to four methyl groups, methoxy, alkyl substituents of C₂ -C₄,F, Cl or Br; C₄ -C₁₀ cycloalkylalkyl; C₄ -C₈ cycloalkylalkyl with 1-2CH₃ ; --CH₂ CH₂ OR₇ ; CH₂ CH₂ CH₂ OR₇ or ##STR2## wherein R₇ is --CH₂CH₃, CH(CH₃)₂, phenyl, --CH₂ CH₁ Cl, --CH₂ CCl₃ ; --CH₂ CH₂ O--_(n') R₈or ##STR3## where R₈ is CH₃, --CH₂ CH₃, --CH(CH₃)₂, phenyl, --CH₂ CH₂ Clor --CH₂ CCl₃ and n' is 2 or 3;

R₂ is H, Cl, Br, F, C₁ -C₃ alkyl, --NO₂, --OCH₃, --SCH₃, CF₃, SO₂ CH₃,N(CH₃)₂ CN; or 4--N═C═O; and

R₃ is H, Cl, Br or CH₃.

Preferred are the following:

(1) A compound of the generic scope where the carbon of R bonded to O isalso bonded to at least one H.

(2) A compound of preferred (1) where R₃ is H and is para to thesulfonyl group.

(3) A compound of preferred (2) where R is C₁ -C₆ alkyl; C₃ -C₆ alkenyl;C₂ -C₄ alkyl substituted with one to four substituents selected from 0-3F, Cl, 0-2 OCH₃ ; C₃ -C₄ alkenyl substituted with 1-3 Cl; C₅ -C₆cycloalkyl; C₅ -C₆ cycloalkenyl; C₅ -C₆ cycloalkyl substituted with upto four methyl groups, methoxy, C₂ H₅ or chloro; C₄ -C₇ cycloalkylalkyl;--CH₂ CH₂ OR₇, ##STR4## or --CH₂ CH₂ CH₂ OR₇ where R₇ is as previouslydefined; --CH₂ CH₂ O--₂ R₈ or ##STR5## where R₈ is as previouslydefined. (4) Compounds of preferred (3) where R₂ is H, Cl, CH₃, NO₂ or4--N═C═O.

More Preferred are:

(5) Compounds of preferred (2) where R is C₁ -C₄ alkyl; C₃ -C₄ alkenyl;C₂ -C₃ alkyl substituted with --OCH₃ or Cl; C₃ alkenyl substituted with1-3 Cl; C₅ -C₆ cycloalkyl; cyclohexenyl; cyclohexyl substituted with 1-3--CH₃ ; or --CH₂ CH₂ OR₇ where R₇ is --C₂ H₅, --CH(CH₃)₂, phenyl, --CH₂CH₂ Cl; or ##STR6## (6) Compounds of preferred (5) where R₂ is asdefined in preferred (4).

(7) Compounds of preferred (5) where R₂ is H.

(8) Compounds of preferred (2) where R is C₁ -C₄ alkyl; C₃ -C₄ alkenyl;C₂ -C₃ alkyl substituted with Cl; --CH₂ CH₂ O--CH₃ or C₂ H₅), ##STR7##or --CH₂ CH₂ CH₂ O(CH₃ or C₂ H₅). (9) Compounds of preferred (8) whereR₂ is as defined in preferred (4).

(10) Compounds of preferred (8) where R₂ is as defined in preferred (7).

The following species are particularly preferred.

Methyl 2-(isocyanatosulfonyl)benzoate;

Ethyl 2-(isocyanatosulfonyl)benzoate;

(1-Methylethyl) 2-(isocyanatosulfonyl)benzoate;

(2-Chloroethyl) 2-(isocyanatosulfonyl)benzoate;

(2-Propenyl) 2-(isocyanatosulfonyl)benzoate;

Methyl 2-(isocyanatosulfonyl)-4-nitrobenzoate;

Methyl 4-chloro-2-(isocyanatosulfonyl)benzoate;

(1-Methylethyl) 2-(isocyanatosulfonyl)-4-nitrobenzoate; and

Methyl 4-isocyanato-2-(isocyanatosulfonyl)benzoate.

Synthesis

Herbicidal compounds of Formula III are prepared as shown in Equation 1by the reaction of an appropriately substitutedo-isocyanatosulfonylbenzoate ester of this invention with an appropriateaminopyrimidine or aminotriazine. Thus, o-isocyanatosulfonylbenzoateesters are important intermediates for the preparation of theseherbicides. ##STR8## wherein R, R₂ and R₃ are as described above and

R₁ is ##STR9## where X and Y are selected from OCH₃ or CH₃ and Z is##STR10##

A mixture of the appropriate sulfonamide, e.g. an o-sulfamoylbenzoateester II such as the methyl ester, which is known in the art, ahydrocarbyl isocyanate such as butyl isocyanate and a catalytic amountof a tertiary amine base such as 1,4-diaza-[2,2,2]bicyclooctane (DABCO)in xylene or other inert solvent of sufficiently high boiling point(e.g. >135°) is heated to approximately 135° C. Phosgene is added to themixture until an excess of phosgene is present as indicated by a drop inthe boiling point. The mixture is then heated further to drive off theexcess phosgene. After the mixture is cooled and filtered to remove asmall amount of insoluble by-products, the solvent and alkyl isocyanateare distilled off in-vacuo leaving a residue which is the crude sulfonylisocyanate I.

The hydrocarbyl isocyanates which are useful in the process are alsodescribed in the above-cited U.S. Pat. No. 3,371,114. As disclosedtherein, the only limitation on the nature of the hydrocarbyl moiety isthat it should be free from substituents which are reactive withphosgene. Preferred in this invention for reasons of efficiency andeconomy are the C₄ -C₁₀ alkyl isocyanates and the C₅ -C₈ cycloalkylisocyanates. For the purposes of this invention, a catalytic quantity ofhydrocarbyl isocyanate will generally consist of an amount equal toabout 0.2 to 1.0 mole of hydrocarbyl isocyanate per mole ofarylsulfonamide.

The phosgenation reaction is carried out in the presence of a catalyticquantity of a tertiary amine base. Any tertiary amine base free ofsubstituents reactive with phosgene may be used. Classes of tertiaryamines which could be used include, but are not limited to, aliphatic,cycloaliphatic, aliphaticaromatic, heterocyclic andaliphaticheterocyclic amines. Preferred for reasons of availability arethose tertiary amines containing from three to ten carbon atoms and oneto two nitrogen atoms. Examples of such bases are pyridine,triethylamine, 1,4-diazabicyclo[2,2,2]octane, 4-dimethylaminopyridine,N,N-dimethylaniline, trimethylamine, N,N-diethylaniline,N-methylpiperidine, and N,N-dimethylpiperazine. Preferred for reasons ofefficiency and economy are 1,4-diazabicyclo[2,2,2]octane andtriethylamine.

The tertiary amine base must be present in a catalytic quantity. Thiswill generally be in the range of about 0.2 to 5.0 grams of base permole of arylsulfonamide.

The process of this invention is generally carried out within atemperature range of about 100°-175° C. although temperature is notcritical. Pressure is also not critical, and atmospheric pressure istypically used.

The time required for the reaction to go to substantial completion maybe readily monitored by techniques familiar to one skilled in the art,e.g., titration of the effluent hydrogen chloride gas or infraredanalysis of the reaction mixture. Typically, the reaction time will bein the range of about 1 to 24 hours.

A suspension of the appropriate arylsulfonamide II in an inert solvent,a catalytic quantity of hydrocarbyl isocyanate and a catalytic quantityof a tertiary amine base are heated, with stirring, to reflux. Thesolvent can be any inert solvent with a boiling point within the rangeof about 100°-200° C.; examples of suitable solvents are xylene,chlorobenzene, mesitylene, toluene, pentachloroethane and octane.Phosgene is then introduced under a refrigerated refulx condenser atsuch a rate that the temperature of the reaction mass is maintained atabout 5° to 8° C. below the boiling point of the solvent. Following thephosgene addition, the reaction mixture is heated to drive off the smallamount of excess phosgene, and is then cooled and filtered to removesmall amounts of any by-product.

The filtered solution can be used directly to make compounds useful asherbicides. Alternatively, the product can be isolated by evaporation ofthe solvent and the hydrocarbyl isocyanate, leaving the high boilingarylsulfonyl isocyanate I as a residue. Generally, these arylsulfonylisocyanates I can be distilled at reduced pressure or used withoutfurther purification.

In Equation 1

R, R₂ and R₃ are as defined above.

Compounds of Formula I in which R₂ is isocyanato may be preparedaccording to Equation 2. ##STR11##

A mixture of the appropriate ester of Formula V, two equivalents of analkyl isocyanate such as butyl isocyanate and a catalytic amount of1,4-diaza[2,2,2]bicyclooctane (DABCO) in xylene or other inert solventof sufficiently high boiling point (e.g. >135° C.) is stirred at 0°-10°C. for 1-4 hours. The mixture is then heated to approximately 135° C.and phosgene added until an excess of phosgene is present as indicatedby a drop in the boiling point. (The mixture is heated further to driveoff excess phosgene.) After the mixture is cooled and filtered to removea small amount of insoluble by-products, the solvent and alkylisocyanate are distilled off in-vacuo leaving residue which is the crudecompound of Formula VI.

Alternatively, the method shown in Equation 3, may be used. A2-sulfamoyl-4-nitrobenzoic acid ester is treated with butyl isocyanateat 80°-135° C. to form the sulfonylurea of Formula VII, followed bycatalytic reduction of the nitro groups at 25°-100° C. and 50-200 psi ofhydrogen pressure to the amino groups and subsequent treatment of theamino compound with phosgene at ˜135° C. to yield the3-isocyanatobenzenesulfonylisocyanate (Formula VIII). ##STR12##

Intermediates of Formula II are prepared, for example, by the proceduresof B. Loev and M. Kormendy, J. Org. Chem. 27, 1703-1709, 2177-2180,2448-2452 (1962), which are herein incorporated by reference.

As shown in Equation 2, compounds of Formula III, wherein R, R₂ and R₃are as defined for Equation 1, and R₁ is as defined for Formula III, areconveniently prepared by reacting an appropriately substitutedo-isocyanatosulfonylbenzoate ester of Formula I with an appropriatelysubstituted aminopyrimidine or aminotriazine of Formula IV. ##STR13##

The reaction of Equation 4 is best carried out in inert aprotic organicsolvents such as methylene chloride, tetrahydrofuran or acetonitrile, atambient pressure and temperature. The mode of addition is not critical;however, it is often convenient to add the sulfonyl isocyanate to astirred suspension of amine IV. Since such isocyanates are liquids, lowmelting solids or are readily soluble in solvents such as those listedabove, their addition can be easily controlled.

The reaction is generally exothermic. In some cases, the desired productis soluble in the warm reaction medium and on cooling crystallizes inpure form. Other products which are soluble in the reaction medium areisolated by evaporation of the solvent, trituration of the solid residuewith solvents such as 1-chlorobutane or ethyl ether, and filtration.

In the following Examples, all temperatures are in °C. and all parts areby weight unless otherwise indicated.

EXAMPLE 1 Methyl 2-(isocyanatosulfonyl)benzoate

A stirred mixture containing 157 g of methyl 2-sulfamoylbenzoate, 73 gof butyl isocyanate 0.3 g of 1,4-diazabicyclo[2,2,2]octane and 1.0 l ofxylene was heated to reflux for one half hour. Phosgene gas was thenpassed into the system under a dry ice reflux condenser allowing thereaction temperature to drop to 120°. This addition was continued untilthe reflux temperature remained at 120° without further phosgeneaddition. The temperature of the reaction mixture was then raised to136° (by removal of the dry ice reflux condenser) after which it wascooled to room temperature and filtered. Evaporation of the filtrateyielded the desired crude sulfonyl isocyanate which could be purified bydistillation at 132°-138° C. under 1.0 to 1.1 mm of mercury pressure.The product is extremely reactive with water so contact with moistureshould be scrupulously avoided.

EXAMPLE 2 Isopropyl 2-(isocyanatosulfonyl)benzoate

To 60.7 g (0.25 mole) of isopropyl 2-sulfamoylbenzoate in 300 ml dry(molecular sieves) xylenes was added 25.0 g (0.25 mole) n-butylisocyanate and 0.1 n-1,4-diazabicyclo[2,2,2]octane. The mixture washeated to reflux temperature and phosgene was slowly bubbled through thesolution for 2 hours.

An infrared spectrum of the reaction mixture indicated formation of thedesired sulfonyl isocyanate (2250 cm⁻¹). The resulting cloudy solutionwas cooled to room temperature and decanted from a small amount of solidimpurity. Evaporation of the resulting clear solution yielded thedesired crude sulfonyl isocyanate, which was used in subsequent stepswithout further purification.

By using the procedures of Examples 1 and 2 or alternatively Equations1-4 with equivalent amounts of the appropriate sulfamoylbenzoate, alkylisocyanate, 1,4-diazabicyclo[2,2,2]octane and phosgene, the compounds ofTable I can be prepared. Infrared absorption peaks listed in Table I forthe isocyanate and o-carbonyl groups are given in reciprocal centimeters(cm⁻¹).

                  TABLE I                                                         ______________________________________                                         ##STR14##                                                                    R                 R.sub.2   R.sub.3 cm.sup.-1                                 ______________________________________                                        CH.sub.2 CH.sub.3 H         H       2250,1725                                 CH.sub.2 CH.sub.2 CH.sub.3                                                                      H         H                                                 CH.sub.2 (CH.sub.2).sub.2 CH.sub.3                                                              H         H       2250,1720                                 CH.sub.2 (CH.sub.2).sub.3 CH.sub.3                                                              H         H                                                 CH.sub.2 (CH.sub.2).sub.4 CH.sub.3                                                              H         H       2215,1720                                 CH(CH.sub.3).sub.2                                                                              H         H       2225,1710                                  ##STR15##        H         H       2215,1705                                 CH.sub.2 CH(CH.sub.3).sub.2                                                                     H         H                                                 CH.sub.2 CH.sub.2 CH(CH.sub.3).sub.2                                                            H         H                                                  ##STR16##        H         H       2250,1725                                 CH.sub.2 (CH.sub.2).sub.8 CH.sub.3                                                              H         H       2210,1710                                 CH.sub.2 CH.sub.2 Cl                                                                            H         H       2200,1710                                 CH.sub.2 CH.sub. 2 OCH.sub.2 CH.sub.3                                                           H         H                                                 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 Cl                                                         H         H                                                 (CH.sub.2 CH.sub.2 O).sub.2 CH.sub.2 CH.sub.2 Cl                                                H         H       2230,1730                                  ##STR17##        H         H       2250,1730                                 CH.sub.2 CHCH.sub.2                                                                             H         H       2250,1725                                 CH.sub.3          4-Cl      H       2200,1715                                 CH.sub.3          4-F       H       2200,1725                                 CH.sub.3          4-Cl      5-Cl                                              CH.sub.3          5-Cl      H       2210                                      CH.sub.3          5-NO.sub.2                                                                              H                                                 n-C.sub.12 H.sub.25                                                                             H         H                                                 (cyclo)C.sub.8 H.sub.15                                                                         5-OCH.sub.3                                                                             H                                                 CH.sub.2 CHCHCH.sub.2 Cl                                                                        4-Cl      5-CH.sub.3                                        CH.sub.2(cyclo)C.sub.6 H.sub.11                                                                 4-CH.sub.3                                                                              H                                                  ##STR18##        5-SO.sub.2 CH.sub.3                                                                     H                                                 CH.sub.2CCl.sub.3 5-CF.sub.3                                                                              H                                                 CH.sub.3          5-N(CH.sub.3).sub.2                                                                     H                                                 CH.sub.3          5-CN      H                                                 CH.sub.3          5-SCH.sub.3                                                                             H                                                 CH.sub.3          5-Br      H                                                 CH(CH.sub.3).sub.2                                                                              5-NO.sub.2                                                                              H                                                 CH.sub.2CHCHCH.sub.2 Cl                                                                         H         H                                                  ##STR19##        H         H                                                  ##STR20##        H         H                                                  ##STR21##        H         H                                                 CH.sub.2CClCCl.sub.2                                                                            H         H                                                  ##STR22##        H         H                                                  ##STR23##        H         H                                                  ##STR24##        H         H                                                  ##STR25##        H         H                                                  ##STR26##        H         H                                                  ##STR27##        H         H                                                  ##STR28##        H         H                                                  ##STR29##        H         H                                                 CH.sub.2CHCH(CH.sub.2).sub.5 CH.sub.3                                                           H         H                                                 CH.sub.2(CH.sub.2).sub.7CHCH.sub.2                                                              H         H                                                 (CH.sub.2).sub.4CHCHCH.sub.3                                                                    H         H                                                 ( CH.sub.2).sub.5 CH.sub.2 Cl                                                                   H         H                                                  ##STR30##        H         H                                                 (CH.sub.2).sub.5 CCl.sub.3                                                                      H         H                                                 CH.sub.2 CBr.sub.3                                                                              H         H                                                 CH.sub.2 CF.sub.3 H         H                                                 CH.sub.2CHClCHClCH.sub.3                                                                        H         H                                                 (CH.sub.2).sub.2OCH.sub.3                                                                       H         H                                                 (CH.sub.2).sub.3OCH.sub.3                                                                       H         H                                                 (CH.sub.2).sub.6OCH.sub.3                                                                       H         H                                                  ##STR31##        H         H                                                  ##STR32##        H         H                                                 CH.sub.2 CH.sub.2 CH.sub.2 OCH(CH.sub.3).sub.2                                                  H         H                                                  ##STR33##        H         H                                                  ##STR34##        H         H                                                 CH.sub.2 CH.sub.2 OCH.sub.2 CCl.sub.3                                                           H         H                                                 (CH.sub.2 CH.sub.2 O).sub.2CH.sub.3                                                             H         H                                                 (CH.sub.2 CH.sub.2 O).sub.2 CH(CH.sub.3).sub.2                                                  H         H                                                  ##STR35##        H         H                                                  ##STR36##        H         H                                                 (CH.sub.2 CH.sub.2 O).sub.3CH.sub.2 CH.sub.2 Cl                                                 H         H                                                  ##STR37##        H         H                                                  ##STR38##        H         H                                                  ##STR39##        H         H                                                  ##STR40##        H         H                                                  ##STR41##        H         H                                                  ##STR42##        H         H                                                  ##STR43##        H         H                                                 CH.sub.2 CH.sub.2cyclo-C.sub.8 H.sub.15                                                         H         H                                                  ##STR44##        H         H                                                  ##STR45##        H         H                                                 CH.sub.2CCC.sub.2 H.sub.5                                                                       H         H                                                 CH.sub.2 (CH.sub.2).sub.3 CCCH.sub.3                                                            H         H                                                 C(CH.sub.3).sub.2CCH                                                                            H         H                                                 CH.sub.2 (CH.sub.2).sub.6 CCCH.sub.3                                                            H         H                                                 CH.sub.3          4-NCO     6-Cl                                              CH.sub.3          4-NCO     H                                                 CH.sub.3          4-NCO     3-Cl                                              CH(CH.sub.3).sub.2                                                                              4-NCO     H                                                 CH.sub.2 CH.sub.3 4-NCO     3-CH.sub.3                                        CH.sub.2 CHCH.sub.2                                                                             4-NCO     H                                                 CH.sub.2 CH.sub.3 4-NCO     H                                                 ______________________________________                                    

EXAMPLE 3N-[(4,6-Dimethylpyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

To 37 g of 2-amino-4,6-dimethylpyrimidine in 500 ml of anhydrousacetonitrile was added 67 g of 2-methoxycarbonylbenzenesulfonylisocyanate with stirring at ambient temperature. The resulting mixturewas thereafter stirred for sixteen hours and then filtered to remove thedesired product which had precipitated as a white solid, m.p. 198°-202°.It showed infrared absorption peaks at 1750, 1700, 1600 and 1550 cm⁻¹,consistent for the desired compound.

EXAMPLE 4N-[(Pyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

With stirring at ambient temperature, 1.0 g of 2-aminopyrimidine in 25ml of anhydrous acetonitrile was added to 2.4 g of2-methoxycarbonylbenzenesulfonyl isocyanate. After stirring that mixturefor 24 hours, the resultant precipitate was filtered off to yield 2.2 gof the desired compound which melted at 188°-192°. Its showing infraredabsorption peaks at 1700, 1680 and 1580 cm⁻¹ is consistent forN-[(pyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide.

EXAMPLE 5N-[(4-Methoxy-6-methylpyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

To a stirred suspension of 1.4 g of 2-amino-4-methoxy-6-methylpyrimidinein 30 ml of anhydrous methylene chloride was added at ambienttemperature 2.4 g of 2-methoxycarbonylbenzenesulfonyl isocyanate. Afterstirring for 16 hours, the foregoing mixture was filtered to removeunreacted amine, and the filtrate evaporated at temperatures up to 40°and reduced pressure. The resultant residue was stirred in 25 ml ofwater, the pH adjusted to 10 by the addition of 50% sodium hydroxide andthe solution filtered. Acidification of the filtrate to pH 3 withhydrochloric acid caused precipitation of the desired product which wasremoved by filtration and dried to yield 0.8 g of product melting at173°-179°. It showed infrared absorption peaks at 1720, 1680, 1630 and1550 cm⁻¹, consistent forN-[(4-methoxy-6-methylpyrimidin-2-yl)-aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide.

EXAMPLE 6N-[(4,6-Dimethoxypyrimidin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

A mixture containing 1.6 g of 2-amino-4,6-dimethoxypyrimidine, 30 ml ofanhydrous methylene chloride and 2.4 g of2-methoxycarbonylbenzenesulfonyl isocyanate was stirred at ambienttemperature and pressure for 16 hours. It was then filtered to removeunreacted amine and the filtrate evaporated at temperatures up to 40°and reduced pressure. The residue thus obtained was stirred in 25 ml ofwater, the pH adjusted to 10 by the addition of 50% aqueous sodiumhydroxide and the solution filtered. Acidification of the filtrate to pH3 caused the formation of a precipitate. Filtration and drying theprecipitate yielded 1.7 g of the desired product, melting at 185°-190°.Its infrared absorption peaks at 1700 and 1710 cm⁻¹ are consistent forthe desired structure and the nuclear magnetic resonance absorptionpeaks at 3.8 and 3.85 are consistent for the two different types ofmethoxy groups brought together in this product.

EXAMPLE 7N-[(4,6-Dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl]-2-(2-chloroethoxycarbonyl)benzenesulfonamide

To 0.7 g of 2-amino-4,6-dimethoxy-1,3,5-triazine in 10 ml anhydrousmethylene chloride solvent was added 1.45 g2-(β-chloroethoxycarbonyl)benzenesulfonyl isocyanate. After stirring atambient temperature for sixteen hours the solvent was removed underreduced pressure, the residue triturated with ether and the solidproduct filtered off, yield 1.21 g, m.p. 171°-174° C. The solid showedinfrared absorption peaks at 1705 and 1715 cm⁻¹, consistent forN-[(4,6-dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl]-2-(2-chloroethoxycarbonyl)benzenesulfonamide.

EXAMPLE 8

N-[(4-Methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]-2-(2-chloroethoxycarbonyl)benzensulfonamide

To 0.7 g of 2-amino-4-methoxy-6-methyl-1,3,5-triazine in 10 ml anhydrousmethylene chloride solvent was added 1.45 g2-(β-chloroethoxycarbonyl)benzenesulfonyl isocyanate with stirring atambient temperature. The mixture was thereafter stirred for sixteenhours. The solvent was evaporated under reduced pressure and the residuetriturated with hexane and filtered to yield 1.72 g of compound whichmelted at 167°-170° C. The solid showed infrared absorption peaks at1700 and 1705 cm⁻¹, consistent forN-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]-2-(2-chloroethoxycarbonyl)benzenesulfonamide.

EXAMPLE 9N-[(4,6-Dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl)]-2-(isopropoxycarbonyl)benzenesulfonamide

To 0.7 g of 2-amino-4,6-dimethoxy-1,3,5-triazine suspended in 5.0 mlanhydrous methylene chloride was added 1.6 g of2-isopropoxycarbonylbenzenesulfonyl isocyanate in 5.0 ml of anhydrousmethylene chloride. The resulting mixture was filtered to remove someunreacted 2-amino-4,6-dimethoxytriazine, the methylene chloride filtratewas evaporated at reduced pressure and the residue triturated withchlorobutane to yield 0.5 g of desired product melting at 192°-195° C.The solid showed infrared absorption peaks at 1705 and 1715 cm⁻¹consistent forN-[(4,6-dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl]-2-(isopropoxycarbonyl)benzenesulfonamide.

EXAMPLE 10N-[(4-Methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]-2-(isopropoxycarbonyl)benzenesulfonamide

To 26.8 g of 2-amino-4-methoxy-6-methyl-1,3,5-triazine in 300 mlanhydrous methylene chloride was added 67.0 g of2-isopropoxycarbonylbenzenesulfonyl isocyanate in 100 ml anhydrousmethylene chloride. The resultant suspension was stirred at ambienttemperature for 72 hours, and filtered to yield 40.0 g of the desiredproduct as a white solid, m.p. 193°-196° C. The solid showed infraredabsorption peaks at 1700 and 1710 cm⁻¹ consistent forN-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]-2-(isopropoxycarbonyl)benzenesulfonamide.

EXAMPLE 11N-[(4,6-Dimethoxy-1,3,5-triazin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

A mixture of 1.6 g of 2-amino-4,6-dimethoxy-1,3,5-triazine, 25 ml ofanhydrous methylene chloride and 2.4 g of2-methoxycarbonylbenzenesulfonyl isocyanate was stirred at ambienttemperature for 16 hours. It was then filtered to remove unreacted amineand the filtrate evaporated at temperatures up to 40° under reducedpressure. The residue was triturated with butyl chloride and filtered toyield the desired compound which melted above 170° with decomposition.

EXAMPLE 12N-[(4-Methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl]-2-methoxycarbonylbenzenesulfonamide

To an anhydrous suspension of 1.4 g of2-amino-4-methoxy-6-methyl-1,3,5-triazine in 25 ml of methylene chloridewas added with stirring at ambient temperature and pressure 2.4 g of2-methoxycarbonylbenzenesulfonyl isocyanate. The mixture was thereafterstirred for 16 hours and filtered. The filtrate was evaporated todryness, the residue was triturated with butyl chloride and the productremoved by filtration. The product thus obtained melted at 165°, and hadabsorption peaks in the infrared at 1550, 1600, 1680 and 1700 cm⁻¹ andin the NMR spectrum at 2.5, 3.65, 4.0 with an aromatic multiplet at7.2-8 ppm.

The activity of compounds of Formula III can be seen in greenhouse andfield tests. The tests are described and the data resulting from themare shown below. The ratings are based on a numerical scale extendingfrom 0=no effect, to 10=maximum effect. The accompanying descriptivesymbols have the following meanings:

C=chlorosis or necrosis

D=defoliation

E=emergence inhibition

G=growth retardation

H=formative effects

U=unusual pigmentation

6Y=abscised buds or flowers

Test A

Seeds of crabgrass (Digitaria spp.), barnyard-grass (Echinochloacrusgalli), wild oats, (Avena fatua), cassia (Cassia tora), morningglory(Ipomoea spp.), cocklebur (Xanthium spp.), sorghum, corn, soybean, rice,wheat and nutsedge tubers (Cyperus rotundus) were planted in a growthmedium and treated preemergence with a nonphytotoxic solvent solution ofthe compounds of Table II. Other batches of seeds and tubers for all ofthe foregoing weed and crop plants were planted at the same time ascontrols. The control plantings were untreated; i.e., neither anycompound nor any solvent was applied. At the same time, cotton havingfive leaves (including cotyledonary ones), bush beans with the thirdtrifoliate leaf expanding, crabgrass with two leaves, barnyardgrass withtwo leaves, wild oats with two leaves, cassia with three leaves(including cotyledonary ones), morningglory with four leaves (includingthe cotyledonary ones), cocklebur with four leaves (including thecotyledonary ones), sorghum with four leaves, corn with four leaves,soybean with two cotyledonary leaves, rice with three leaves, wheat withone leaf, and nutsedge with three-five leaves were sprayed with anonphytotoxic solvent solution of the compounds of Table II. Othergroups of all the same weed and crop plants were sprayed with the samenonphytotoxic solvent so as to provide control plants. Preemergence andpostemergence treated plants and controls were maintained in agreenhouse for sixteen days, then all treated plants were compared withtheir respective controls and rated visually for response to treatment.The data in Table II shows that the compounds of this invention are veryeffective as herbicides.

    TABLE II      POST-EMERGENCE     Morning-     Barnyard- Wild       kg/ha Bushbean     Cotton glory Cocklebur Cassia Nutsedge Crabgrass grass Oats Wheat Corn     Soybean Rice Sorghum      ##STR46##      0.42.0 9C9C 9C9C 10C10C 10C9C 9C9C 9C9C 9C9C 10C10C 9C9C 9C9C 9C9C     9C6C,9G 10C10C 9C10C      ##STR47##      0.4 9C 9C 10C 9C 9C 9C 5C,9G 9C 9C 9C 10C 9C 5C,9G 9C      ##STR48##      0.4 9C 9C 10C 9C 9C 10C 5C,8G 9C 9C 9C 9C 9C 8C 9C       PRE-EMERGENCE  kg/ha Morningglory Cocklebur Cassia Nutsedge Crabgrass     Barnyardgrass Wild Oats Wheat Corn Soybean Rice Sorghum      ##STR49##      0.42.0 9G 9G 9G9G 8G9G 10E10E 9G9G 9H9H 3C,9H3C,9H 9H9H 10E10E 9H9H     10E10E 10E10E      ##STR50##      0.4 9G 9G 9G 10E 9H 9H 9H 9H 10H 9H 10E 9H      ##STR51##      0.4 9G 9G 9G 10E 9H 9H 9H 9H 9H 10E 10E 9H       POST-EMERGENCE     Morning-     Barnyard- Wild   Soy-    kg/ha     Bushbean Cotton glory Cocklebur Cassia Nutsedge Crabgrass grass Oats     Wheat Corn bean Rice Sorghum      ##STR52##      0.4 9C 9C 10C 9C -- 9C 10C 10C 10C 10C 10C 9C 10C 10C      ##STR53##      0.4 9C 5U,5C,9G 10C 9C 9C 9C 9C 10C 4C,7G 3C,7G 10C 9C 10C 9C      ##STR54##      2 5C,10D 5C,9G 5C,9G 9C 9C 9C 9C 9C 9C 10C 5U,9C 9C 9C 9C       PRE-EMERGENCE  kg/ha Morningglory Cocklebur Cassia Nutsedge Crabgrass     Barnyardgrass Wild Oats Wheat Corn Soybean Rice Sorghum      ##STR55##      0.4 9H 9G 9G 10E 10E 9H 9H 9H 10E 9H 10E 9H      ##STR56##      0.4 9G 9G 9G 9G 9H 9H 9G 9G 9G 9H 10E 9G      ##STR57##      2 9C 9G 9C 10E 4C,9G 9H 9H 9H 9G 9H 10E 9H       POST-EMERGENCE     Morning-     Barnyard- Wild   Soy-    kg/ha     Bushbean Cotton glory Cocklebur Cassia Nutsedge Crabgrass grass Oats     Wheat Corn bean Rice Sorghum      ##STR58##      0.4 9D,9G 6C,9G 9C 6C,9G 5C,8G 7G 2A 9C 2C 1C 9H 9C 4C,8G 2C,9G      ##STR59##      0.4 9D,9G 7C,9G 10C 9C 5C,8G 8G 0 5C,9H 8G 5C,8G 5C,9H 3C,9G 5C,9G     3C,9G      ##STR60##      0.4 9C 9C 10C 10C 10C 10C 5C,8G 6C,9H 2C,6G 2C 10C 5C,9G 5C,8G 5C,9G       PRE-EMERGENCE  kg/ha Morningglory Cocklebur Cassia Nutsedge Crabgrass     Barnyardgrass Wild Oats Wheat Corn Soybean Rice Sorghum      ##STR61##      0.4 9G 9G 8G 10E 0 9H 8G 2G 2C,8G 8H 10E 9G      ##STR62##      0.4 9G 10E 9G 10E 6G 9H 2C,9H 9G 2U,9H 9H 10E 9H      ##STR63##      0.4 9G 9G 6C,9G 10E 2C,6G 2C,9H 9G 5G 9G 9H 10E 2C,9G

What is claimed is:
 1. A compound selected from: ##STR64## wherein R is C₁ -C₁₂ alkyl; C₃ -C₁₀ alkenyl; C₃ -C₁₀ alkynyl; C₂ -C₆ alkyl substituted with one to four substituents selected from 0-3 atoms of F, Cl, Br or 0-2 methoxy groups; C₃ -C₆ alkenyl substituted with 1-3 atoms of F, Cl or Br; C₅ -C₈ cycloalkyl; C₅ -C₈ cycloalkenyl; C₅ -C₈ cycloalkyl substituted with substituents selected from one to four methyl groups, methoxy, alkyl substituents of C₂ -C₄, F, Cl or Br; C₄ -C₁₀ cycloalkylalkyl; C₄ -C₈ cycloalkylalkyl with 1-2 CH₃ ; --CH₂ CH₂ OR₇ ; CH₂ CH₂ CH₂ OR₇ or ##STR65## where R₇ is --CH₂ CH₃, CH(CH₃)₂, phenyl, --CH₂ CH₂ Cl, --CH₂ CCl₃ ; --CH₂ CH₂ O)_(n') R₈ or ##STR66## where R₈ is CH₃, --CH₂ CH₃, --CH(CH₃)₂, phenyl, --CH₂ CH₂ Cl or --CH₂ CCl₃ and n' is 2 or 3;R₂ is H, Cl, Br, F, C₁ -C₃ alkyl, --NO₂, --OCH₃, --SCH₃, CF₃, SO₂ CH₃, N(CH₃)₂, CN, or 4--N═C═O; and R₃ is H, Cl, Br or CH₃ with the proviso that when R is other than C₃ -C₁₀ alkynyl, then R₂ must be 4--NCO.
 2. A compound of claim 1 where the carbon of R bonded to O is also bonded to at least one H.
 3. A compound of claim 2 whereR₃ is H and is para to the sulfonyl group.
 4. A compound of claim 3 whereR is C₁ -C₆ alkyl; C₃ -C₆ alkenyl; C₃ -C₁₀ alkynyl; C₂ -C₄ alkyl substituted with one to four substituents selected from 0-3 F, Cl, 0-2 OCH₃ ; C₃ -C₄ alkenyl substituted with 1-3 Cl; C₅ -C₆ cycloalkyl; C₅ -C₆ cycloalkenyl; C₅ -C₆ cycloalkyl substituted with up to four methyl groups, methoxy, C₂ H₅ or chloro; C₄ -C₇ cycloalkylalkyl; --CH₂ CH₂ OR₇, ##STR67## or --CH₂ CH₂ CH₂ OR₇, --CH₂ CH₂ O--₂ R₈ or ##STR68##
 5. Compounds of claim 4 whereR₂ is H, Cl, CH₃, NO₂ or 4--N═C═O.
 6. Compounds of claim 3 whereR is C₁ -C₄ alkyl; C₃ -C₄ alkenyl; C₃ -C₁₀ alkynyl; C₂ -C₃ alkyl substituted with --OCH₃ or Cl; C₃ alkenyl substituted with 1-3 Cl; C₅ -C₆ cycloalkyl; cyclohexenyl; cyclohexyl substituted with 1-3 --CH₃ ; or --CH₂ CH₂ OR₇ where R₇ is --C₂ H₅, --CH(CH₃)₂, phenyl, --CH₂ CH₂ Cl; or ##STR69##
 7. Compounds of claim 6 whereR₂ is H, Cl, CH₃, NO₂ or 4--N═C═O.
 8. Compounds of claim 6 where R₂ is H.
 9. Compounds of claim 2 whereR is C₁ -C₄ alkyl; C₃ -C₄ alkenyl; C₂ -C₃ alkyl substituted with Cl; --CH₂ CH₂ O--(CH₃ or C₂ H₅), ##STR70## or --CH₂ CH₂ CH₂ O(CH₃ or C₂ H₅).
 10. Compounds of claim 1 whereR₂ is H, Cl, CH₃, NO₂ or 4--N═C═O.
 11. Compounds of claim 9 where R₂ is H.
 12. The compound of claim 10, methyl 4-isocyanato-2-(isocyanatosulfonyl)benzoate. 